Acquired infections are an unfortunate fact of hospital stays. It is not uncommon for an infectious organism to spread throughout an entire section of a hospital, particularly within an intensive care unit. Every once in a while, a particularly troublesome organism will affect an entire hospital, and eradication of the organism requires the use of multiple, expensive and toxic antibiotics. Such epidemics cost the hospital, the patient, and insurance companies untold amounts in direct costs, add to the patient's length of stay, and increase morbidity and mortality.
As a result, absolutely every health care worker is encouraged, expected, and required by the hospital as well as the Occupational Safety and Health Administration (OSHA) to wear gloves when they come into contact with patients. Many hospitals now conduct mandatory "universal precautions" courses for all employees that come into contact with patients, prompted by continuing concern with the acquired immune deficiency syndrome virus. These courses, typically repeated on a regular basis, teach that every situation where a patient is to be examined must be considered for the spread of infection. For example, all instruments used to examine patients must either be disposable (such as otoscopicspecula, tongue blades, cotton swabs, and thermometers), or be sterilizable between uses.
It is thus considered unprofessional, irresponsible, and a violation of universal precautions for a health care worker to not wear gloves when examining patients or to neglect to wash hands thoroughly between patients. In such an environment, gloves in various sizes and antiseptic hand cleaners are conspicuously located on cabinets, shelves, and racks, everywhere in sight.
However, the use of certain instruments by hospital personnel must also play a role in hospital-acquired epidemics. Consider, for example, a respiratory intensive case unit. Respiratory patients, who are typically at an increased risk of developing pneumonia, usually have foreign objects inserted into their bodies such as breathing tubes. Respiratory therapists and nurses use stethoscopes every time they visit each and every patient. The stethoscope may become contaminated while examining the lungs of an infected patient, and the therapist then uses the inadequately clean stethoscope on the next patient. Even if the therapist were to clean his stethoscope and hands, certain microbes known to cause pneumonia are resistant to the most commonly used antibiotics, and contaminants may remain in hard-to-clean crevices. As a result, even the most careful of therapists will unavoidably transfer infections from one patient to the next.
In an emergency room, the situation is similar. All care-givers use a stethoscope, placing it on the chest and back of almost every single patient they encounter. Sometimes the stethoscope is put to the groin or the abdomen to listen for other sounds.
But emergency room patients often have slimy, sweaty skin, and may be unshowered or totally unkempt after being rushed into the hospital. In the worst scenario, trauma room patients arrive in the emergency room covered in blood, HIV-status unknown. As a result, accepted and often mandatory precautions for the arrival of a new patient include donning of goggles, mask, plastic coverall gown, shoe covers, and of course, gloves.
When the patient arrives, the physician always performs the potential life-saving step of applying a stethoscope to listen to the patient's chest immediately, without regard to whatever fluids may cover the chest. The stethoscope is then thrown around the neck, until it is used again on the next patient. The stethoscope is rarely, if ever, cleaned between patients. The bloodied stethoscope may also be stored in the pocket of the physician's white lab coat, where it comes into contact with other items in the pockets. In a large city hospital, this scenario may be repeated many times in a single evening.
In neglecting the role of the stethoscope in the practice of universal precautions, a significant threat to the health and lives of health care workers and patients alike as been permitted to continue. Patients, doctors, hospitals and regulatory agencies have just not adequately considered the stethoscope and the potentially huge health risk it represents.
That is not to say, however, that certain people have not recognized the potential for the spread of infection via the stethoscope.
For example, U.S. Pat. No. 4,461,368 issued to Plourde on Jul. 24, 1984 discusses the problem generally. That patent proposes the use of a sterile diaphragm cover consisting of a membrane sheet mounted on a rigid rim member. The rigid rim member contains one or more tabs adapted to be engaged over the outer edge of the stethoscope.
Devices such as that shown in the Plourde patent are not in widespread use, however, probably for several reasons. First, the covers must be custom-made for each individual type of stethoscope. Since stethoscope heads tend to be of different designs, and since the selection of a particular stethoscope depends upon the application to which it is put, as well as a matter of the physician's or nurse's personal preference, many different versions of a Plourde-type cover would have to be kept in inventory in a typical hospital. It is probably not practical nor realistic to expect a hospital to stock custom covers for each type of stethoscope head.
Furthermore, an emergency room physician is unlikely to have the time to search for a cover which fits his particular type of stethoscope. And, even if the physician could quickly find the correct type of cover, the installation of such a cover onto the stethoscope would appear to be unnecessarily cumbersome, since a pair of tabs must be aligned with a corresponding portion of a stethoscope ring.
U.S. Pat. 4,871,046 issued to Turner also discusses a type of stethoscope cover. This cover is formed from a type of loose-fitting, plastic bag which may be easily dispensed from a roll. However, covers such as this one are also not in widespread use, probably for several reasons.
First, the corners of the bag are prone to fold over, and the sides of bag itself are prone to wrinkle during application to the skin. These folded or wrinkled sections of bag material interfere with the accuracy and level of sound transmitted to the stethoscope.
Second, the bag only provides a loose fit around the stethoscope head. The loose fit, in turn, means that infectious contaminants may still find their way onto the stethoscope, via the openings left by the loose fitting bag. The potential for transmission of disease has thus not been eliminated if the stethoscope is subsequently used in the unprotected state before being cleaned again.
What is needed is a disposable, clean stethoscope cover which can be used with a wide variety of stethoscope types. It should not provide any path for infectious disease to reach the stethoscope head.
The cover should be easy to install and remove from the stethoscope, to encourage its widespread use.
It should also be designed to avoid interference with sound transmission during its use.
SUMMARY OF THE INVENTION
It is an object of this invention to help prevent the spread of infectious disease via stethoscopes in a typical hospital environment.
The invention is a stethoscope head diaphragm cover formed exclusively from a disk of suitably elastic material such as latex. The cover is pre-formed in the same general shape as a stethoscope head, with the outer diameter of the latex cover in its relaxed state being smaller than that the diameters of common stethoscopes. The cover thus fits the stethoscope head snugly after being installed, regardless of the particular geometry of the stethoscope head.
The elastic material is selected to be thin enough to avoid muffling the sounds through the stethoscope diaphragm, while being thick enough to prevent violation organisms or fluids, and thick enough to prevent breakage during installation.
In the preferred embodiment, the cover also preferably has a rolled edge formed in the same manner as a common prophylactic. The rolled edge greatly assists with installation and removal of the cover.
The cover provides a tight fit around all of the surfaces of the stethoscope typically coming in contact with a patient. This prevents transmission of fluids containing potentially infectious organisms to even the peripheral surfaces of the stethoscope.
The tight-fitting cover also does not interfere in any way with the transmission of sound to the stethoscope diaphragm.
It is easy to install and remove from the stethoscope, and disposable and inexpensive to manufacture. It may be made to a universal size which fits all of the various stethoscopes now in use.